If a subject to be photographed is something that moves, such as a man or an animal, it is generally difficult to photograph an image at the moment the subject is in a suitable condition to be photographed. In particular, when taking a group photo or the like, it is very difficult to photograph an image at the moment all of a plurality of subjects are in a suitable condition to be photographed, for example, at the moment they are looking at the camera, smiling, and not blinking. Therefore, in many cases, at least one of the subjects on a photographed image is in an unfavorable condition.
In this respect, a technique known in the art is a method of generating a composite image where all of a plurality of subjects are in a good condition from a base image and another image (referred to as a comparative image) in which the plurality of subjects are photographed at different moments. For example, in an image compositing method disclosed in Patent Document 1, the contour of the face (or the face and body) of a subject is detected from each of a base image and a comparative image, and the area defined by each contour is extracted as a partial image. Then, if a subject is in a good condition in the base image, the subject area is left as it is. If a subject is in an unfavorable condition in the base image but in a good condition in the comparative image, the subject area of the comparative image is pasted over the subject area of the base image. A composite image where all subjects are in a good condition is thus generated.
On the other hand, techniques of generating the so-called cinemagraph are known in the art (for example, see Patent Document 2). A cinemagraph is a motion picture in which a predetermined area of the image moves while the other area remains still, which is generated by photographing a moving subject multiple times and compositing a series of the obtained images.